Bankers on both sides of the Atlantic have lost the chance to collect "jackpot" fees of £345m following the collapse of US drugs giant Pfizer's £69bn bid for its British rival AstraZeneca.

Investment banking experts said the banks, lawyers, accountants and PR firms advising on the deal could have collected between £300m and £345m if the biggest ever foreign takeover of a British company had gone ahead.

Peter Hahn, a former managing director at Citigroup and now finance lecturer at Cass Business School, said advisers typically collect fees worth 0.5% of the deal, which would have worked out at £345m if AstraZeneca had accepted Pfizer's last £55-a-share offer.

However, the fees could have clocked up even higher if the takeover battle had become even more contentious. Bankers and other advisers collected £240m advising on Kraft's £12bn takeover of Cadbury in 2010, which works out at 2% of the deal.

Hahn said Pfizer's banking advisers would be feeling pretty sore because investment banking adviser contracts are generally structured so that without a deal there is no fee.

"There'll be some senior guy in New York, it could have easily cost him several million," Hahn said.

One banker potentially nursing such a loss is Fares Noujaim, who as Bank of America Merril Lynch executive vice president was Pfizer's lead banker.

The collapse of the deal is a rare blot on the Lebanese-American's dealmaking copybook. He was instrumental in Vodafone's $130bn sale of its 45% stake in the Verizon Wireless mobile phone company to Verizon Communications, and has advised on deals worth a total of $450bn.

Other rainmakers losing out on a bumper potential payday include Andrew Mee, Bank of America Merril Lynch's head of international mergers & acquisitions, and fellow senior bankers at the same firm Michael Findlay and Geoff Iles.

Pfizer was also advised by Guggenheim Partners, an investment banking advisory service founded by the great-grandson of Solomon Guggenheim, as well as by JP Morgan.

Hahn said the bankers would be extremely angry that months of long nights and weekends spent working on the deal had gone to waste. "Of course, there will be huge disappointment, but it's a high risk game," he said. "There's no question it [pay] is about success."

He said it was unlikely that the bankers would have already spent the larger bonuses they expected to collect as a result of the deal. "The one lesson I learnt as a investment banker is you don't spend the money until it's in your account."

AstraZeneca's bankers – Robey Warshaw, Evercore Partners, Goldman Sachs and Morgan Stanley – will collect fees for defending the company from Pfizer's approaches, but could have picked up more cash if Pfizer had taken a hostile bid direct to Astra shareholders.

Alongside the bankers there will be lawyers, accountants and PR people who could have collected from the deal.

Hahn pointed out that Pfizer's complex and controversial plan to move to the UK to save millions in tax would have been an extra big moneyspinner for accountants and lawyers.

London's two biggest PR firms – Brunswick (which acts for Pfizer) and RLM Finsbury (working for AstraZeneca) – will also lose out from ongoing work promoting or criticising the deal.

A senior PR executive at a different firm said Brunswick chairman Alan Parker would be "devastated" at the collapse of the deal. "The contract would have been in the high hundreds of thousands into seven figures," the PR man said. "They will be devastated by this, it would have made up a meaningful part of the bonus – it would be the difference between getting a Ferrari or not."